Storage container and evaporator for refrigerators



Feb. 24, 1948. w. L. MORRISON STORAGE CONTAINER AND EVAPORATOR FOR REFRIGERATORS Filed Aug. 14, 1944 4 Sheets-Sheet 1 O l I i I 721/ 672 2507'- WZZZa'raZ 1. (2757775072, %9 M M Feb. 24, 1948. w. MORRISON 2,436,592

STORAGE CONTAINER AND EVAPORATOR FOR REFRIGERATORS Filed Aug. 14, 1944 4 Sheets-Sheet 2 Inf/6722507" WE'ZZara" Z Jforrzhon OQ- JM-M Feb. 24, 1948. w. MORRISON 2,

STORAGE CONTAINER AND EVAPORATOR FOR REFRIGERATORS Filed Aug. 14, 1944 4 She ets-Sheet 3 n 5 o m w 3 M C 3 M 4 v x u. n C 6M & vi 6 n m u I. 3 WW J1 UM Z5 M u T h W n mx. m fi. L m n U 3 i U H m u a n w n n m n u i I u q ,F. I e m m L I m I Mm M N v Feb. 24, 1948. w. 1.. MORRISON STORAGE CONTAINER AND EVAPORATOR FOR REFRIGERATORS Z Sheets-Sheet 4 Filed Aug. 14, 1944 Patented Feb. 24, 1948 UNITED STATES PATENT OFFICE STORAGE CONTAINER AND EVAPORATOR FOR REFRIGERATORS Willard L. Morrison, Lake Forest, Ill.

Application August 14, 1944, Serial No. 549,430

Claims. (Cl. 62-126) This invention relates to refrigerating apparatus and has for one purpose to provide an improved evaporator.

Another purpose is to provide an evaporator which circumferentially defines and surrounds an open topped storage area.

Another purpose is to provide an evaporator which shall be economical and simple to manufacture.

Another purpose is to provide an evaporator unit which permits the employment of a minimumvolume of a volatile refrigerant.

Another purpose is to provide an evaporator surrounding a storage space, which evaporator distributes the volatile evaporant substantially uniformly throughout the area of the evaporator which surrounds the storage space.

Other purposes will appear from time to time in the course of the specification and claims.

I illustrate the invention more or less diagrammatically in the accompanying drawings, in which:

Figure I is a side elevation;

Figure 2 is a section, on an enlarged scale, on the line 2-2 of Figure 1;

Figure 3 is a section on the line 3-3 of Figure 2;

Figure 4 is a vertical section on an enlarged scale through the evaporator member proper.

Figure 5 is a similar section through a variant form; and

Figure 6 is a section on the line 6-6 of Fig. 5.

Like parts are indicated by like characters throughout the specification and drawings.

In the invention herein illustrated, I employ a base i which may be generally flat and shown as having a generally plane top surface 2 and a generally plane bottom surface 3 mounted on skids 4. The evaporator is illustrated as having an outer cylinder 5 and an inner cylinder 6. The inner and outer cylinders may be welded or otherwise secured to each other at their upper and lower edges as shown in Figure 4 at l and 8. I may for example employ seam welding. The cylinders in the completed container or evaporator, are spaced sufficiently apart to define a refrigerant receiving space which extends entirely about the evaporator and substantially from top to bottom of the evaporator. This may be a space of very low clearance. It may for example approximate .026 to .028, this being given as an example rather than as a rigid restriction to any particular space range. The point is that it is practical, in the present structure, to employ a close clearance between the two cylinders.

In the form of the device herein shown, the inner cylinder 6 is. shown as substantially a true cylinder although it might be slightly tapered and has a smooth, preferably unbroken cylindrical face which circumferentially surrounds and defines the storage space of the refrigerator unit. The outer cylinder is provided with two outer beads or concavo-convex projections 9, l0. These serve as distributors for the refrigerant which is shown as entering the bottom inlet passage II and escaping through the top outlet passage I2. I illustrate the upper distributor 9 as substantially larger than the lower distributor 10 because it receives gas whereas the bottom distributor receives the refrigerant as an unexpanded liquid. The two cylinders may be spaced apart by the initial projections l3 on the outer cylinder, of which any suitable number may be employed for providing a uniform effective spacing between the two cylinders and may also employ intermediate smaller distributor beads as shown at l4 which are shown as extending entirely about the outer cylinder. One or more may be employed, depending upon the height of the evaporator.

After the two cylinders have been formed and joined, I may apply any suitable bottom member l5 with its centering projection l5a, which may be welded to the cylinders as at [6.

With reference to the method of manufacture of the evaporator, I may find it advantageous to roll both the inner and the outer cylinder from sheet stock. They may be rolled into substantially correct form and dimensions and may then be seam welded or otherwise secured at their abutting edges. In forming the outer cylinder 5, I find it advantageous to pass the sheet stock through forming rolls which roll out the manifolds or distributors 9, l0 and I4, and which also form the dimples or spacing indentations l3. Since the forming tools do not of themselves form part of the present invention, I do not illustrate them. It will be understood, however, that I may employ any suitable forming rolls or forming tools for producing requisite shape or form of the two cylinders. After the two cylinders have been initially formed,the inner cylinder and the outer cylinder are interfltted. For ease of interfitting and for accuracy of manufacture, I find it desirable initially to form the cylinders with a somewhat larger clearance than their final clearance. Thereafter and preferably before they are permanently secured together, I employ any suitable internal expander for directing a substantially uniform outward thrust throughout the area of assasca the inner face of the inner cylinder i. The thrust is continued until the inner cylinder engages the dim les l3 which provide means for uniformly spacing the two cylinders apart. Whereas I have illustrated and described the use of spacing dimples integral with the outer cylinder 5, it will be iind erstood that any other suitable spacing means may be employed. r under some circumstances, the spacing means may be dispensed with although they constitute an eillcient mode of obtaining a uniform clearance between the inner face of the outer cylinder I and the outer face of the inner cylinder 6. Thus when the expanding tool causes the inner cylinder 8 to engage the points of the dimples l4, then the two cylinders are properly spaced. The forming tool forms the parts to a true cylinder.

It will be noted that the distributors 9 and iii are spaced somewhat inwardly of the edges of the cylinders. Thi is advantageous as giving adequate space for seam welding at the points I and 8. The distributors or manifolds so'placed do not interfere with the use of a wheel type seam welder. Either during the last welding operation or directly afterwards, I may add the bottom element l5. Any suitable form of bottom may be employed. I may for example employ a drawn cup bottom. However, the bottom may be added either before or after or at the time of welding the two cylinders 8 and 6.

It will be understood that whereas I find it convenient and economical to form the outer and inner cylinders and 6 of sheet stock, welded along a longitudinal seam, I may also employ drawn cylinders. For example, it is under some circumstances advantageous to draw the inner cylinder in order to have it seamless. In that event the bottom may be integral with the inner cylinder and the inner cylinder will be outwardly expanded against the outer cylinder, the welding following the final expansion.

It will be understood that under some circumstances it may be advantageous to weld the cylinders together at top and bottom before the final expansion of the inner cylinder in relation to the outer, takes place.

The refrigerating cycle and structure do not of themselves form a part of the present invention. Any suitable refrigerating apparatus may be used.

In the drawings I have illustrated a refrigerating apparatus comprising a motor 22 .and a compressor 23, driven from the motor by a belt 24. The gas, when compressed by the compressor, passes out through the pipe II and is then delivered to the top of the condenser 39. The liquid then passes from the condenser through the pipe 40 into the receiving tank 4|. The liquid passes from the receiver 4| through pipe 42 to an expansion valve I2 from which the liquid at low pressure passes by the duct I l to the receiving enlargement or manifold III of the outer cylinder 5. 54 is any suitable bulb for assisting the automatic control of the temperature of the evaporator. The discharge passage i2 returns the gas from the upper enlargement 9 to the compressor.

The compressor condenser unit may be mounted upon a lateral extension of the base I and may be surrounded by an suitable housing 80. The evaporator is shown as positioned and supported on a block or disc ll of insulating material, which is initially held against lateral movement on the base I by the dowel 62. The member 6| is recessed to receive the centering projection Ho. 63 is, any suitable concentric surrounding housing which constitutes the exterior wall of the refrigerator cabinet. It may be of relatively thin relatively flexible material, such as sheet metal. When the insulation 84 is crowded down into the space between the evaporator and the outer wall 63, a firm structure i provided which surrounds and is reinforced by the evaporator. Any suitable top cover 65 may be employed for the insulation and a removable top closure 66 is used to protect the storage area from above. Any suitable insulation 61 may surround the upper portion of the evaporator care being taken to avoid the use of any heat transmitting material. The cover 66 is at all points located above the space surrounded by the evaporator and does not extend down into the pool of cold air which is maintalned in the space surrounded by the evaporator.

Referring to the form of evaporator shown in Figures 5 and 6, I illustrate various changes over the form of Figure 4. In Figure 5 the liquid refrigerant is delivered to a top distributor 9a along the liquid pipe Ha. It then passes downwardly through the space between the cylinders 5a and 8a to the bottom collector Illa, from which the evaporated refrigerant may pass by the pipe in. Since the bottom distributor must accommodate evaporated refrigerant it is shown as larger than the top distributor 9a. It is important to economize the volume of refrigerant employed. I find it advantageous to substitute for the projections I3 of Figure 4 the elongated ridges I3a of Figures 5 and 6, which perform the same function but which partially fill the space between the cylinders and reduce the necessary volume of refrigerant. In the form of Figure 5 it will be understood that a very small clearance is necessary between the upper ends of the cylinder 5a and 6a. The clearance between the cylinders may increase from top to bottom of the evaporator. Thi incrcase is not shown in the drawings since it may be relatively slight. It will be understood that I prefer to provide a generally progressive increase in clearance, which is necessary to accommodate the gas resulting from the evaporation of the initially liquid refrigerant.

It is immaterial whether the projections l3 and the intermediate distributors I4 are formed in the inner or in the outer cylinder. In Figure 4, I illustrate the members l4 as being formed in the outer cylinder, whereas in Figure 5 the corresponding members a are formed in the inner cylinder. This relationship may be reversed. The same is true of the distributors 9 and 9a and I0 and Illa. However, since, they are of substantially greater bulk it is preferable that they extend outwardly from the outer cylinder. However, of the two members making up the evaporator, the outer one 5 or 5a is inherently the stronger because it is subjected only to tensile stresses but the inner one 6 or Go is more difllcult to make suillciently strong because it is subjected to collapsing pressure and it is advantageous to put the distributing member 14 or Na on 6 or Go. That is on the inside, because it very greatly increases the resistance of that member to collapsing pressure. In the form of Figure 5, I find it advantageous to deliver the liquid to the top distributor 8a, the clearance between the two cylinders being sufliciently slight to prevent any damaging excess downward flow of liquid. The liquid is able to flow relatively slowly through the very small clearance between the opposed cylinders, and evaporation takes place throughout substantially the entire area of the outer face of the inner cylinder to.

It will be realized that whereas I have described and shown a practical and operative device, nevertheless many changes may be made in the size, shape, number and disposition of parts without departing from the spirit of my invention. I therefore wish my drawings and description to be taken as in a broad sense illustrative and diagrammatic.

The use and operation of my invention are as follows: v

I provide an evaporator structure for refrigerators which circumferentially defines and su-rrounds a storage space. In the use of the device herein shown, the storage space may be employed to receive and store foods or other substances. It may be cooled suillciently to treat materials, such as metals, where cold temperature treatment is desired.

I rovide an evaporator structure which has an effective cooling surfacethroughout its entire inner area. The relation between the cooled area of the evaporator and the volume of the space cooled is such that I obtain a substantial avoidance of an temperature difierential between the stored material and the refrigerant which would be effective to cause thermosyphonic action. This is particularly important in connection with the storage of food stuffs, such as meats. The result is an avoidance of deterioration or desiccation of the stored substances and the reduction to a minimum of the depth of frost on the inner surface of the evaporator.

I also provide an evaporator which is economical to manufacture, which is highly efficient in operation and which constitutes an adequate central frame or support or skeleton for the refrigerator. The outer and inner cylinders and 6 may b truly cylindrical or they may be slightly tapered. They may be integrally drawn, or one or both of them may be rolled from sheet and formed with welded abutting edges.

In the actual manufacture of the device after the two cylinders have been formed, they are interfitted or telescoped and are secured together at their upper and lower edges, and are provided with an accurate clearance and proper final form by the expansion of the inner cylinder 6 in relation to the outer cylinder 5. Any suitable spacing means may be employed but I find the integral dimples I3 highly efficient.

In the use of the device, the refrigerant in liquid unexpanded form, flows along the inlet ii to the bottom distributor or manifold l0, which receives a substantial volume of the liquid. In the course of its evaporation, the refrigerant rises upwardly about the entire outer circumference of the inner cylinder 6. The spacers iii are of insufllcient area to interfere with this upward rise. The top manifold or distributor 9 receives the refrigerant in evaporated or gaseous form and the gas passes oiI through the discharge outlet I2. I find that the intermediate and preferably smaller distributors it are of assistance in maintaining the uniform distribution of the refrigerant.

In the variant form of Figure 5, as earlier pointed out, I illustrate a structure which is particularly adapted for delivering the refrigerant to the upper end of the evaporator.

It will be understood that there is no metal path of heat transmission between the outer covering 53 and the evaporator structure. The member 85 may for example be formed of some suitable insulating material. Beneath it and between it and the insulation body 81 is a member l of insulating material Iii extending to the upper gclige of a cylindrical ring of insulating material I claim:

1. In an'open topped evaporator and storage structure for refrigerators, concentric, generally vertically axised inner and outer cylinders having spacing means therebetween adapted to space them slightly apart, said cylinders being sealed together at their ends to define therebetween an evaporator space and having a bottom member enclosing the'storage space surrounded by said evaporator, said evaporator having a circumferential distributor at one end, means for delivering a liquid refrigerant to said distributor and means for withdrawing theevaporated refrigerant from said evaporator space at a point remote from said distributor, said distributor being located adjacent the top of the evaporator, the clearance between said cylinders increasing progressively downwardly from said distributor.

2. In an open topped evaporator and storage structure for refrigerators, concentric, generally vertically axised inner and outer cylinders having spacing means therebetween adapted to space them slightly apart, said cylinders being sealed together at their ends to define therebetween an evaporator space and having a bottom member enclosing the storage space surrounded by said evaporator, said evaporator having a circumferential distributor at each end, means for delivering a liquid refrigerant to the upper distributor and means for withdrawing evaporated refrigerant from the lower distributor, the clearance between cylinders being sufiiciently close to impede and delay the otherwise free downward flow of the refrigerant between the cylinders, and an additional distributor extending circumferentially about the evaporator intermediate the upper and lower distributor.

3. In an open topped evaporator and storage structure for refrigerators, concentric, generally vertically axised inner and outer cylinders having spacing means therebetween adapted to space them slightly apart, said cylinders being sealed together at their ends to define therebetween an evaporator space and having a bottom member enclosing the storage space surrounded by said evaporator, said evaporator having a circumferential distributor at each end, means for delivering a liquid refrigerant to the upper distributor and means for withdrawing evaporated refrigerant from the lower distributor, the clearance between said cylinders being initially very small and increasing progressively downwardly from the upper distributor.

4. In an evaporator and storage structure for refrigerators, generally concentric inner and outer cylinders sealed at the ends to define between them an evaporator space, one of said cylinders having formed therein circumferentially extending distributors located at opposite ends of the evaporator, the other cylinder having formed therein an intermediate distributor extending circumferentially about the evaporator, and a closure wall for one end only of said evaporator, adapted to define, with said evaporator an open topped storage space.

5. In an evaporator and storage structure for refrigerators, generally concentric inner and outer cylinders sealed at the ends to define between them an evaporator space, one of said cylinders having formed therein circumferentially extending distributors located at opposite ends of the evaporator. the other cylinder hm.

formed therein an intermediate distributor ex-.

tending circumferentially about the evaporator, one of said cylinders having formed therein integ'ral means for spacing said cylinders apart. 5

and a closure wall'for one end only 01 said evaporator, adapted to define, with said evaporator an open topped storage space.

WILLARD L. MORRISON.

REFERENCES CITED The following references are of record in the file oi. this patent:

Number Jensen Feb. 14, 1933 

